OCC has published part 3 of their review of the Danger Den Water Box Plus Case

A quote from the article:

We have looked at the case and pump for our project and now have reached the next item in the cooling loop, the radiator. This is the device that actually transfers the heat generated by the cpu, graphics card and pump from the liquid medium to the surrounding atmosphere. This is accomplished the same way as on a motor vehicle. With the motor vehicle the heat is generated by the combustion cycle instead of a piece of silicon. The heat is transfered to the liquid coolant (antifreeze), and that is continuously recirculated through the motor by a water pump. The radiator has a fan pulling air through it, exhausting the heat to the atmosphere and lowering the temperature of the coolant. In all, its a pretty efficient process that is the same across both platforms.